/Engine/Source/Runtime/Engine/Classes/Components/ReflectionCaptureComponent.h
Generally called each tick to recapture any queued reflection captures. In some cases, it's also called from Editor utility functions or commands. Set "bInsideTick" to true if called from inside a Tick function, indicating a render frame is already active, and the capture doesn't need to start one.
static void UpdateReflectionCaptureContents ( [UWorld](API\Runtime\Engine\Engine\UWorld) * WorldToUpdate, const TCHAR * CaptureReason, bool bVerifyOnlyCapturing, bool bCapturingForMobile, bool bInsideTick )